While there are similarities between the LT1/4 heads and later Vortec heads, they are totally different animals. All LT1/4 heads are designed for reverse cooling- you can't just bolt them on an earlier engine and go. Also, the intake bolt pattern is completely different from all other SBC intake bolt patterns- it's not like a Vortec, not like 87-up heads and not like 86-down heads. Modifying them to work on earlier engines has been done but it's probably not worth the hassle.
As GM refers to their engine families, the Vortec engines are technically modified and updated "Gen I" small blocks, even though they came out after the "Gen II" LT1/4 engines. There's nothing much in a Vortec motor, aside from those killer Vortec heads, that didn't exist for 10+ years before on other factory small blocks- roller cams, one piece rear main seals, centerbolt valve covers, sequential fuel injection, serpentine accessory drive systems- nothing much new under the sun. Crazy, ain't it?
Vortec heads were used on late 90s truck engines before they went to the LSx-based engines. They use standard coolant flow and will bolt on to an eariler block with no problems. They do use their own vortec-specific intake bolt pattern but aftermarket carburetor intakes for them are easily obtained from all the usual manufacturers.
1990 454SS pickup. Original "tow truck motor" 454 upgraded to something a little more "aggressive." Seems pretty stout but the fuel bill is nuts.
78 Malibu. Inherited with only 35K on the odo! Mild 383 with Weiand 142 blower on top. Mid 12s appears to be the best it's gonna do on street rubber. Runs so good I may never drive it again.
"Last remaining QJet tuner on planet Earth!"
Last edited by Damon : 04-07-2007 at 08:16:40 PM.